The motor of a hermetic compressor usually comprises, mounted inside its hermetic shell, a rotor and a stator, the latter being formed by a main coil and a secondary coil, said motor being fed by an electric current from a power source external to said hermetic shell, by connecting an appropriate wiring to a power inlet plug, mounted externally to the hermetic shell and which is electrically connected to the stator of the electric motor.
In a known construction, in order to connect the stator to the power inlet plug of the hermetic shell through the interior of the latter, some copper wires of the stator, generally three, are connected to a cable by clamping a metallic piece, joining each copper wire to the cable, which is then connected to the shell. After clamping the two parts together, for each wire, the formed assembly receives a thermal retractible insulating cover, which protects said connection thus obtained. After the connection, the whole assembly is positioned inside the coils that form the motor.
This construction presents some disadvantages, such as difficult automation, for example in the clamping steps, which also results in low quality of the obtained electric connections, with a high number of defects and rejections, for example due to low efficiency of the intended connection and to failures in the process for obtaining said connection.
In another known construction, the electric connections of the motor to the shell of the compressor occur through an electric connection device, which receives each copper wire from the motor coils to be electrically connected to the shell of the compressor, and which lodges each of said wires in a respective contact cradle. While this solution allows for automation and improves the quality of the electric connections between the motor and the hermetic shell of the compressor, as compared to the electric connections obtained by clamping, the known constructions for an electric connection device present deficiencies in relation to the form of retaining said devices inside the hermetic shell of the compressor.
In one of the known solutions for affixing the electric connection device inside the hermetic shell of the compressor, one of the parts which forms said device and which is provided with teeth is affixed, by interference, in the stator of the electric motor. In another known solution, the part to be affixed to the stator is provided with flanges, which are fitted into a portion of the stator, before fastening thereof.
In the first fixation option, the disadvantages reside in the fact that the fixing means is easily broken, due to aging of the material, generally plastic, and the possibility of occurring relative movements between the electric connection device and the stator wire, which can lead, with time, to material fatigue.
Moreover, this construction allows the occurrence of undesired vibrations in the connection. In the second fixation option, the disadvantages result from the fact that, for each flange of the electric connection device to be fastened to the stator, there is loss of a fastening point thereof. In the known fixations, three fastening points of the stator are lost with this process.